Method and apparatus for pasteurization, hydrolysis and carbonization

ABSTRACT

This invention proposes the use of Thermal Hydrolysis (or Thermal Carbonization) at different temperatures and pressures in alternate waste streams to achieve an optimal mix of high digestion rates and pasteurization rates while still achieving large viscosity reduction. In the disclosed embodiments means of combining Thermal Hydrolysis (or Thermal Carbonization) and Pasteurization including but not limited to placing the waste streams in parallel, placing them in series, utilizing heat input in parallel and heat exchangers in series are explored to optimize hydrolysis rates, minimize the use of high pressure tanks, optimize energy used, and manage viscosity characteristics of the solids.

RELATED APPLICATION

This application claims priority to U.S. provisional application No.62/398,936 entitled A Method and Apparatus for Pasteurization withThermal Hydrolysis, filed Sep. 23, 2016. The entire disclosure of theprovisional application is incorporated herein by reference.

BACKGROUND

Thermal hydrolysis is now becoming a widely practiced technology toimprove digestion rates (usually at temperatures greater than 100degrees Celsius, and simultaneously pasteurize wastewater solids (orother wastes) and to decrease the viscosity of wastewater solids andother wastes. The combined thermal hydrolysis and pasteurization attemperature greater than 100 degrees Celsius will henceforth be referredto as Thermal Hydrolysis. Other forms of hydrolysis include chemicalhydrolysis (such as alkaline hydrolysis, acid hydrolysis), enzyme(natural or manufactured) hydrolysis and electron beam (E-Beam)hydrolysis. The individual form or combination (2 or more) of thermal,alkaline, acid, natural or manufactured enzyme, E-beam hydrolysis isgenerically henceforth called hydrolysis. Pasteurization can also bepracticed at atmospheric pressure (henceforth simply referred to aspasteurization to differentiate from high pressure thermalhydrolysis >100 C). While the digestion rates and pasteurization can beincreased by operating the process at lower temperatures and atatmospheric pressure, the viscosity reduction of some types of solids isbest achieved at higher temperatures and pressures. ThermalCarbonization is the practice of heating sludge to temperatures (atdifferent retention times) approximately greater than 180° C. underpressure and up to approximately 220□, henceforth referred to as ThermalCarbonization. The scope of the invention is to develop an approach tomanage and co-mix streams of wastes by performing the thermal orhydrolysis treatment at one, two (or more); depending on number ofparallel or series waste streams) temperatures to achieve the optimizedsolution. The hydrolysis or pasteurization step can be replaced by athermal carbonization step. Or, alternative some of these processes canbe combined in a single step. For example, pasteurization and chemicalhydrolysis can be combined in a single step. This way enhanceddigestability and higher loading rate of solids can be achieved whileminimizing requirement of volume of high pressure vessels and achievingoverall pasteurization of all of the solids.

SUMMARY OF THE INVENTION

In this invention we propose the use of pasteurization, hydrolysis(inclusive of thermal hydrolysis) and/or carbonization at a plurality oftemperatures and pressures in alternate waste streams in order toeffectively achieve an optimal mix of high digestion rates andpasteurization rates while still achieving large viscosity reduction andhigh dewatered cake solids concentrations. This may be achieved throughthe use of separate waste streams feeding alternate Thermal Hydrolysis(or Thermal Carbonization) and Pasteurization processes beforeco-mixing.

In some embodiments of the present disclosure waste activated sludge andprimary sludge would feed a Thermal Hydrolysis (or ThermalCarbonization) and Pasteurization Process in parallel while being heattreated before being mixed in an Anaerobic digester and ultimatelydewatered such that the end cake product is separated from the residualcentrate/filtrate. In other embodiments, while the sludge would feed thetreatment processes in series, the heat input would occur in parallel inthe Thermal Hydrolysis and Pasteurization process. In some otherembodiments, a heat exchanger would connect the Thermal Hydrolysis (orThermal Carbonization) process to the Pasteurization process such thatonly the mass of the sludge is treated in parallel by each process,while the heat transfer occurs prior to the digester. In some suchembodiments the heat exchange connection will still exist betweenThermal Hydrolysis (or Thermal Carbonization) and Pasteurization,however the Thermal Hydrolysis (or Thermal Carbonization) mass flow willalso be in series with Pasteurization such that neither mass nor heatflow in parallel. In yet other embodiments optional blending may be usedin lieu of the forced anaerobic digester, such that each parallelprocess can go through dewatering separately prior to cake digestion,and centrate/filtrate separation. Finally a mix of the aforementionedvariations is envisioned in the present disclosure.

There may further exist other reactions within the spirit of theinvention not explicitly described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings which are incorporated in and form a part ofthe specification, illustrate several embodiments of the inventionwherein:

FIG. 1 is a graph depicting Time vs Temperature for solids post-ThermalHydrolysis (or Thermal Carbonization) Process (THP) with or withoutrecovery as shown where t=time in hours, and Temp=temperature in degreesCelsius.

FIG. 2 is a graph showing the apparent viscosity profiles for solidsconcentration of about 10.5% before and after THP where treatment is at130, 150, or 170 degrees C. respectively.

FIG. 3 is a graph representing the Thermal Pretreatment Temperature indegrees C. vs Viscosity at a shear rate of 7/s (mPa-s).

FIG. 4 is a flowchart depicting waste activated sludge and primarysludge feeding a Thermal Hydrolysis (or Thermal Carbonization) andPasteurization Process in parallel while being heat treated before beingmixed in an Anaerobic digester and ultimately dewatered such that theend cake product is separated from the residual centrate/filtrate.

FIG. 5 is a flowchart showing waste activated sludge feeding a ThermalHydrolysis (or Thermal Carbonization) and simultaneously primary sludgefed Pasteurization Process in series, as heat input occurs in parallelin the Thermal Hydrolysis (or Thermal Carbonization) and Pasteurizationprocess.

FIG. 6 is a flowchart representing waste activated sludge and primarysludge feeding a Thermal Hydrolysis (or Thermal Carbonization) andPasteurization Process in parallel while a heat exchanger connects theThermal Hydrolysis (or Thermal Carbonization) process to thePasteurization process such that only the mass of the sludge is treatedin parallel by each process, while the heat transfer occurs prior to theanaerobic digester.

FIG. 7 is a flowchart displaying waste activated sludge feeding aThermal Hydrolysis (or Thermal Carbonization) and simultaneously primarysludge fed Pasteurization Process in series, as heat input occurs inparallel in the Thermal Hydrolysis (or Thermal Carbonization) andPasteurization process while a heat exchanger connects the ThermalHydrolysis (or Thermal Carbonization) process to the Pasteurizationprocess such neither the sludge treatment nor the heat transfer occur inparallel prior to the anaerobic digester.

FIG. 8 is a flowchart presenting waste activated sludge and primarysludge feeding a Thermal Hydrolysis (or Thermal Carbonization) andPasteurization Process, respectively, in parallel while being heattreated before being mixed in an optional blending tank or remaining inparallel before being ultimately dewatered such that the cake is furtheranaerobically digested while separated first from the residualcentrate/filtrate.

FIG. 9 is a flowchart depicting waste activated sludge feeding a ThermalHydrolysis (or Thermal Carbonization) and simultaneously primary sludgefed Pasteurization Process in series, as heat input occurs in parallelin the Thermal Hydrolysis (or Thermal Carbonization) and Pasteurizationprocess prior to the mix being dewatered and the cake is furtheranaerobically digested while separated first from the centrate/filtrate.

FIG. 10 is a flowchart illustrating waste activated sludge and primarysludge feeding a Thermal Hydrolysis (or Thermal Carbonization) andPasteurization Process in parallel while a heat exchanger connects theThermal Hydrolysis (or Thermal Carbonization) process to thePasteurization process such that only the mass of the sludge is treatedin parallel by each process, while the heat transfer occurs prior tobeing mixed in an optional blending tank or remaining in parallel beforebeing ultimately dewatered such the cake is further anaerobicallydigested while separated first from the centrate/filtrate

FIG. 11 is a flowchart depicting waste activated sludge feeding aThermal Hydrolysis (or Thermal Carbonization) and simultaneously primarysludge fed Pasteurization Process in series, as heat input occurs inparallel in the Thermal Hydrolysis (or Thermal Carbonization) andPasteurization process while a heat exchanger connects the ThermalHydrolysis (or Thermal Carbonization) process to the Pasteurizationprocess such neither the sludge treatment nor the heat transfer occur inparallel prior to the mix being dewatered and the cake is furtheranaerobically digested while separated first from the centrate/filtrate

FIG. 12 is a flowchart that shows an implementation of hydrolysis(thermal, alkaline, acid, E-Beam or a combination thereof) associatedwith recuperative thickening. Influent solids is optionally pasteurizedor optionally thickened and optionally added directly to digestion, or,upstream or downstream of the hydrolysis or recuperative thickeningprocess.

FIG. 13 is a flowchart showing an implementation of pre-pasteurizationand hydrolysis ((thermal, alkaline, acid, E-Beam or a combinationthereof) associated with recuperative thickening. In this case theinfluent thickened solids is optionally sent partly of fully topasteurization and the remainder is sent to a digester either upstreamor downstream of hydrolysis step.

FIG. 14 is a flowchart showing an implementation of pre-digestionhydrolysis (thermal, alkaline, acid, E-Beam or a combination thereof)with separate solids and liquid digestion.

FIG. 15 is a flowchart that shows pasteurization and hydrolysis(thermal, alkaline, acid, E-Beam or a combination thereof) beforeanaerobic digestion.

It is envisioned that FIGS. 4-11 may be preceded by a thickening ordewatering device in certain embodiments. The dewatering step can alsobe a final step immediately after hydrolysis or carbonization.

DETAILED DESCRIPTION OF THE INVENTION

Some of the preferred embodiments of the present disclosure areillustrated in the attached drawings:

FIG. 1 is a graph depicting Time vs Temperature for solids post-ThermalHydrolysis (or Thermal Carbonization) Process with or without recoveryas shown where t=time in hours, and Temp=temperature in degrees Celsius.

FIG. 2 is a graph showing the apparent viscosity profiles for solidsconcentration of about 10.5% before and after THP where treatment is at130, 150, or 170 degrees C. respectively.

FIG. 3 is a graph representing the Thermal Pretreatment Temperature indegrees Celsius versus Viscosity at a shear rate of 7/s (mPa-s).

FIG. 4 is a flowchart depicting waste activated sludge 402 feeding aThermal Hydrolysis (or Thermal Carbonization) 404 as Heat Input isprovided 406 and a heat exchanger cycles residual heat 408.Simultaneously Primary Sludge 410 feeds a Pasteurization Process 412 inparallel as Heat Input is provided 414 and a heat exchanger cyclesresidual heat 416 before being mixed in an Anaerobic Digester 418 (whichalso sends residual heat to the aforementioned heat exchangers 408,416)and sent to dewatering 420 so that the end cake produced 422 isseparated from the residual centrate/filtrate 424.

FIG. 5 is a flowchart depicting waste activated sludge 502 feeding aThermal Hydrolysis (or Thermal Carbonization) 504 as Heat Input isprovided 506 and a heat exchanger cycles residual heat 508 before thesludge is sent to Pasteurization 512 in series. Simultaneously PrimarySludge 510 feeds the Pasteurization Process 512 as Heat Input isprovided 514 and a heat exchanger cycles residual heat 516 before beingmixed in an Anaerobic Digester 518 (which also sends residual heat tothe aforementioned heat exchangers 508,516) and sent to dewatering 520so that the end cake produced 522 is separated from the residualcentrate/filtrate 524.

FIG. 6 is a flowchart representing waste activated sludge 602 feeding aThermal Hydrolysis (or Thermal Carbonization) 604 as Heat Input isprovided 606 and a heat exchanger cycles residual heat 608.Simultaneously Primary Sludge 610 feeds a Pasteurization Process 612 inparallel as Heat Input is provided 614 and a heat exchanger cyclesresidual heat 616 before being mixed in an Anaerobic Digester 618 (whichalso sends residual heat to the aforementioned heat exchangers 608,616)and sent to dewatering 620 so that the end cake produced 622 isseparated from the residual centrate/filtrate 624. Heat is balancedbetween the parallel thermal hydrolysis (or thermal carbonization) 604and Pasteurization 612 processes through the use of a heat exchanger 626directly connecting the two.

FIG. 7 is a flowchart displaying waste activated sludge 702 feeding aThermal Hydrolysis (or Thermal Carbonization) 704 as Heat Input isprovided 706 and a heat exchanger cycles residual heat 708 before thesludge is sent 725 to Pasteurization 712 in series. SimultaneouslyPrimary Sludge 710 feeds the Pasteurization Process 712 as Heat Input isprovided 714 and a heat exchanger cycles residual heat 716 before beingmixed in an Anaerobic Digester 718 (which also sends residual heat tothe aforementioned heat exchangers 708,716) and sent to dewatering 720so that the end cake produced 722 is separated from the residualcentrate/filtrate 724. Heat is also balanced between the parallel THP704 and Pasteurization 712 processes through the use of a heat exchanger726 directly connecting the two so that neither mass nor heat truly runin parallel in this embodiment.

FIG. 8 is a flowchart presenting waste activated sludge 802 feeding aThermal Hydrolysis (or Thermal Carbonization) 804 as Heat Input isprovided 806 and a heat exchanger cycles residual heat 808.Simultaneously Primary Sludge 810 feeds a Pasteurization Process 812 inparallel as Heat Input is provided 814 and a heat exchanger cyclesresidual heat 816 before being mixed in an optional blending tank 818 orremaining in parallel before being sent to dewatering in either case 820such that the cake digestion process final cake product 822 is separatedfrom the residual centrate/filtrate 824.

FIG. 9 is a flowchart depicting waste activated sludge 902 feeding aThermal Hydrolysis (or Thermal Carbonization) 904 as Heat Input isprovided 906 and a heat exchanger cycles residual heat 908 before thesludge is sent 925 to Pasteurization 912 in series. SimultaneouslyPrimary Sludge 910 feeds the Pasteurization Process 912 as Heat Input isprovided 914 and a heat exchanger cycles residual heat 916 prior to themix being sent to dewatering 918 and the centrate/filtrate 920 separatedfrom the cake digestion processes final cake product 922.

FIG. 10 is a flowchart illustrating waste activated sludge 1002 feedinga Thermal Hydrolysis (or Thermal Carbonization) 1004 as Heat Input isprovided 1006 and a heat exchanger cycles residual heat 1008.Simultaneously Primary Sludge 1010 feeds a Pasteurization Process 1012in parallel as Heat Input is provided 1014 and a heat exchanger cyclesresidual heat 1016 before being mixed in an optional blending tank 1018or remaining in parallel before being sent to dewatering in either case1020 such that the cake digestion process final cake product 1022 isseparated from the residual centrate/filtrate 1024. Heat is balancedbetween the parallel THP 1004 and Pasteurization 1012 processes throughthe use of a heat exchanger 1026 directly connecting the two.

FIG. 11 is a flowchart depicting waste activated sludge 1102 feeding aThermal Hydrolysis (or Thermal Carbonization) 1104 as Heat Input isprovided 1106 and a heat exchanger cycles residual heat 1108 before thesludge is sent 1125 to Pasteurization 1112 in series. SimultaneouslyPrimary Sludge 1110 feeds the Pasteurization Process 1112 as Heat Inputis provided 1114 and a heat exchanger cycles residual heat 1116 prior tothe mix being sent to dewatering 1118 and the centrate/filtrate 1120separated from the cake digestion processes final cake product 1122.Heat is also balanced between the parallel THP 1104 and Pasteurization1112 processes through the use of a heat exchanger 1126 directlyconnecting the two so that neither mass nor heat truly run in parallelin this embodiment.

FIG. 12 is a flowchart showing an implementation of hydrolysis (thermal,alkaline, acid, E-Beam or a combination thereof) associated withrecuperative thickening. Influent solids is optionally pasteurized oroptionally thickened and optionally added directly to digestion, or,upstream or downstream of the hydrolysis or recuperative thickeningprocess.

FIG. 13 is a flowchart showing an implementation of pre-pasteurizationand hydrolysis ((thermal, alkaline, acid, E-Beam or a combinationthereof) associated with recuperative thickening. In this case theinfluent thickened solids is optionally sent partly of fully topasteurization and the remainder is sent to a digester either upstreamor downstream of hydrolysis step.

FIG. 14 is a flowchart showing an implementation of pre-digestionhydrolysis (thermal, alkaline, acid, E-Beam or a combination thereof)with separate solids and liquid digestion.

FIG. 15 is a flowchart that shows pasteurization and hydrolysis(thermal, alkaline, acid, E-Beam or a combination thereof) beforeanaerobic digestion.

It is envisioned that FIGS. 4-11 may be preceded by a thickening ordewatering device in certain embodiments. The pasteurization process inthe above figures can be replaced with a hydrolysis or thermalcarbonization process; or can also be combined with hydrolysis. Theutility of the proposed components for these embodiments is explicitlydetailed below:

Reactors and Process Streams: The solids are heated in reactors. Theheat for pasteurization can be provided using solar cells that candirectly or indirectly heat sludge. The fluid can be air, water or otherheat transfer material. The reactor can be operated as a continuous flowthrough process, a batch process, a sequencing batch process, or aplug-flow process. Any pressurized solids can be depressurized eitherslowly or rapidly. The reactor can be heated using steam, heatexchangers or heat pumps and pressurized using solar, thermal, hydraulicor mechanical approaches. Single or multiple reactors can be comprisedwithin two or more influent heat and/or mass flow streams that areeither fully in parallel or are in series (such as a tributary) to anoverall heat and/or mass flow stream or in combination of parallel orseries as desired. The heat and mass flows streams can be uncoupled asdesired. For example, the heat stream could flow in as a tributary for afully parallel mass flow stream.

Proposed Treatment Temperature for Reactors: The invention proposes amethod or apparatus wherein temperature of wastewater solids (or otherproducts and wastes) is increased between 60 and 220 degrees Celsius(<180° C. is thermal hydrolysis and >180° C. is thermal carbonization)to increase feed solids concentration to anaerobic digestion, decreasedigester volume requirements, increase throughput rates of anaerobictreatment, increase cake solids, improve microbial hydrolysis rates,inactivate pathogens or indicators, or decrease head loss, mixing orpumping energy, and that reduces viscosity of the solids. Additionalhydrolysis (chemical (acid, alkaline or other compounds), manufacturedenzyme, naturally produced enzyme such as through aerobic thermophilicpretreatment), or E-beam) or combination of approaches can be mixed into achieve desired performance and much lower temperatures than thosetypically preferred (100° C.-180° C.) for thermal hydrolysis. In oneapproach of this method or apparatus, a more viscous or more slowlyhydrolysable solids such as waste activated sludge, cellulosic waste,slowly digestible organic waste is thermally (or other forms orcombinations of hydrolysis) hydrolyzed at higher temperatures between 60and 180 degrees Celsius (or up to 220° C. for thermal carbonization) andwherein the more easily hydrolysable (non-rate limiting solids) such asprimary solids, food waste or any other organic waste or products ispasteurized at lower temperatures between 60 and 100 degrees Celsius.More than two streams with multiple wastes and temperatures are alsopossible. This approach allows for managing and optimizing the use oftemperature and heat for the two streams and to simultaneously achieveoptimized reductions in viscosity (and thereby increased processthroughput rates), while achieving pasteurization, increased digestionrates and/or increased dewatered cake solids. The two (or multiple)streams could be in parallel or series of each other, with thepossibility of heat transfer/sharing or stream mixing. In the case ofseries approach the lower temperature stream is usually pasteurizeddownstream of the higher temperature stream (with mass or heat transferoccurring between the two (or multiple) streams).

Proposed Viscosity Characteristics: The higher viscosity solids(approximately >2500 mPa-s when operated at a solids concentration ofabout 10%, a temperature of about 20 C, and a shear rate of 7 s-1) orless hydrolysable/digestible solids (requiring an overall solidsretention time approximately greater than 5-7 days) are typically heatedto higher temperatures (and its corresponding pressure) of 100 to 180degrees Celsius (or 220° C. for thermal carbonization) or undergo otherforms of hydrolysis (alkaline, acid, enzymic (externally manufactured(at a manufacturing process for such production) or naturally produced),E-Beam. Lower viscosity solids (approximately <3500 mPa-s when operatedat a solids concentration of about 10%, a temperature of about 20° C.,and a shear rate of 7 s-1) are typically heated to lower temperatures of60 to 100 degrees Celsius. Solids in between 2500 mPa-s and 3500 mPa-scan be heated in either of the two approaches to create the appropriate‘mix’ of viscosity characteristics for anaerobic digestion.

Proposed Thickened/Dewatered Solids Concentration: The solids aretypically pre-thickened or dewatered to approximately 3-15% solidsbefore the heat ‘reactions’, although much higher solids of 35% is alsopossible. After the heating reaction, the solids can be either diluted,thickened or dewatered to a solids concentration of between 7-55%, thehigher solids concentration occurring to promote ‘dry digestion’. Forthe special case of dry digestion, a single stream is permitted (amultiple mix stream is not needed), where the thickening/dewatering stepoccurs between the heating reactors and the anaerobic digestion process.The filtrate or centrate liquor obtained after thickening/dewatering(when thickening or dewatering occurs between ‘heating reactors’ and‘digestion’ steps) can be used as a carbon source for biologicalnutrient removal or anaerobic digestion as needed. Thethickening/dewatering that occurs before the heating step could allowfor concomitant phosphorus release in the filtrate on centrate ifdesired. Dewatering can also be the final step of the overall process(without including a digestion step thereafter).

In another embodiment of this invention, the stream for thehigh-temperature hydrolyses (or carbonization) process is dewatered to asolids concentration of >8, while the stream for the pasteurizationprocess is thickened to a solids concentration <8% in order to managethe relative viscosities and the heat balances of the two streams.

In some embodiments of the present disclosure, a heat generator canregulate higher temperatures of 135 to 180 degrees Celsius as reservedfor the higher viscosity solids or less digestible solids.

In an another approach to manage the solids concentration, a portion ofthe solids is sent to the pre-treatment involving high temperature andhigh solids concentration is controlled in order to match a pre-definedhydraulic retention time in the down-stream anaerobic digester. Dilutionwater can be added to additionally manage the solid concentration and/orhydraulic retention time. This management of the solids concentrationand time will allow for the achievement of stable digestion. In someembodiments, the management of solids concentration and dilution willaddress inhibition (such as from ammonia) or toxicity.

Proposed use of the filtrate or centrate (after the heating reaction).The removed liquid of the dewatering process can consist of refractorymaterial or substance that is produced during the thermal hydrolysis orcarbonization processes. The liquid can be harvested as a sterilizedproduct for agriculture, fermentation feed stock, antimicrobial blendsor for chelation. The removed liquid of the dewatering process cancomprise humic and fulvic substances. The removed liquid could consistof inhibitors or growth promoters of bacteria for selecting specificreactions within microbial cycles. The production of these constituents(such as chelators or other inhibitors) in this liquid can be controlledusing sensors (such as ultraviolet (UV) scan, UV, Raman, infrared, FTIR,or other forms of spectroscopy). This control can thus manage (throughfeedback control controlled using a sensor that controls a pump, valveor other devices), the temperatures used for the thermal hydrolysis orcarbonization reactions. The thermal hydrolysis and carbonizationreactions are expected to in many cases produce these refractorycompounds at the very point of impact of high temperature steam or otherheat exchange material (by scalding, scorching, charring or otherwisechanging molecular structures of the sludge) on a sludge particle. Theproduction of the refractory constituents can be decreased or mitigatedby better ‘direct heat’ dissipation by any method available includingthe use of water baths, lower temperature steam baths, better mixing(flash mixing or other approaches of rapid mixing), or any otherapproaches that are available for such purpose of preventing thescalding, scorching, charring or otherwise changing molecular structuresof the sludge.

The production of refractory substances (refractory material) during thethermal hydrolysis or carbonization processes can be managed orcontrolled using a sensor that controls a pump, valve or other devices.The production of refractory substances during thermal hydrolysis orcarbonization can be minimized through more rapid heat dissipation usingbetter mixing, heat transfer or heat management approaches.

In another embodiment of the invention, the temperature can be increasedusing solar energy or solar cells that directly or indirectly heatsludge.

Proposed use of thickened or dewatered solids. The sterilized solids canbe bioaugmented with specialized micro-organism prior to anaerobicdigestion, prior to or after dewatering, or prior to agricultural use ofsolids. These microorganisms could comprise specialized bacteria orfungi (such as nitrogen fixers or Trichoderma) that could promote itsagricultural use. The specialized micro-organisms could also bespecifically used to consume excess hydrogen in digesters, produceexcess hydrogen in digesters, or to increase Firmicutes overBacteroedetes ratio, or to increase anaerobic nitrogen fixation.

Recuperative Thickening: Recuperative thickening (the thickening ofsludge in the recirculation loop of an anaerobic digester) is alsopossible as shown in some figures. The influent solids of the twostreams can be added at different locations prior to the recuperativethickening process, hydrolysis process, pasteurization process ordirectly to digestion.

Pasteurization to address regrowth of indicators and pathogens: Aminimum temperature of 75 degrees Celsius for about 30 minutes isusually required to address resuscitation and regrowth of indicator andpathogens, especially if approximately more than 3-4 logs (10³-10⁴colony forming units/gram dry solids, 10³-10⁴ most probable number/g drysolids, or 10³-10⁴ unique DNA copies/g dry solids of these organisms arepresent. Thermophilic or high temperature aerobic pretreatment (that canalso improve hydrolysis) can also be used in lieu of, or in combinationwith pasteurization.

Proposed approach to improve hydrolysis/particle destruction rates inanaerobic digester: Microbial hydrolysis/particle destruction rates areimproved by decreasing microbe to substrate (especially particulatesubstrate) proximity (by thickening/dewatering the solids),microbe-microbe proximity (by thickening/dewatering the solids), orincreasing diffusivity through decreased viscosity (associated withdestruction/release of structured or bound water). Forms of hydrolysisinclude, thermal, chemical, enzymic or E-Beam or combinations thereof.Chemical hydrolysis can include but is not limited to acid or alkalinehydrolysis. Alkaline hydrolysis can include (but not limited to) the useof potassium hydroxide, sodium hydroxide, calcium oxide/hydroxide ormagnesium oxide/hydroxide or a combination of these chemicals. Acidhydrolysis can be achieved using naturally produced (VFA) or syntheticacids.

Proposed control of temperature based on viscosity characteristics. Thepasteurization temperature can be controlled directly or indirectlybased on viscosity characteristics of the solids. The viscosity could bemeasure directly or through indirect control based on head loss in pumpsor torque in a mixer, or any such approach. Direct viscosity basedcontrol can occur using an in-line or off-line or lab measured viscosityvalue using a shear rate as required.

Proposed control of viscosity characteristics using solids dilution. Thesolid dilution or thickening is used to control viscosity of solidsthrough direct or indirect viscosity measurement as desired. Theviscosity could be measure directly or through indirect control based onhead loss in pumps or torque in a mixer, or any such approach. Directviscosity based control can occur using an in-line or off-line or labmeasured viscosity value using a shear rate as required.

In some embodiments of the present disclosure, a refractory substance isproduced. The production of refractory substances during the thermalhydrolysis or carbonization processes can be managed or controlled usinga sensor that controls a pump, valve or other devices. The production ofrefractory substances during thermal hydrolysis or carbonization can beminimized through more rapid heat dissipation using better mixing, heattransfer or heat management approaches.

In another embodiment of the invention, the temperature can be increasedusing solar energy or solar cells that directly or indirectly heatsludge.

The invention also relates to a method for Hydrolysis (or ThermalCarbonization) treatment wherein temperature of wastewater solids isincreased between 60 and 220 degrees Celsius to increase feed solidsconcentration to digestion, decrease digester volume requirements,increase throughput rates of anaerobic treatment, increase cake solids,improve microbial hydrolysis rates, inactivate pathogens or indicators,or decrease head loss, mixing or pumping energy, and that reducesviscosity of the solids, wherein the mostly waste activated sludge,cellulosic waste, slowly digestible organic waste is hydrolyzed (usingthermal, thermophilic aerobic, chemical, enzyme, or electron beam) attemperatures between 60 and 180 degrees Celsius (or up to 220 degreesCelsius for thermal carbonization) and wherein the mostly primarysolids, food waste or any other organic waste or products is pasteurizedat temperatures between 60 and 100 degrees Celsius. The highertemperatures for hydrolysis or carbonization approaches are reserved forthe higher viscosity solids or less digestible solids

In some embodiments of the present disclosure, the solids produced aftertreatment are dewatered to increase cake solids of a content of 7-55%total dry solids prior to anaerobic digestion or composting of thesesolids.

In some embodiments of the present disclosure, the stream for thehigh-temperature hydrolyses process is dewatered to a solidsconcentration greater than approximately 8%, while the stream for thepasteurization process is thickened to a solids concentration less thanapproximately 8%.

In other embodiments, the portion of the solids sent to thepre-treatment involving high temperature and high solids concentrationis controlled in order to match a pre-defined hydraulic retention timein the down-stream anaerobic digester.

In another embodiment of the invention, removed liquid of the dewateringprocess is used as a carbon source for biological nutrient removal,anaerobic digestion. The removed liquid of the dewatering process may beharvested as a sterilized product for agriculture, fermentation feedstock, antimicrobial blends, or chelation. The removed liquid of thedewatering process can increase breakdown of humic-towards fulvicsubstances if targeted.

In another embodiment of the invention, solids produced after additionalanaerobic digestion are dewatered to increase cake solids to a contentof 7-55% total dry solids.

In another embodiment of the invention, the solids produced beforetreatment are dewatered to increase cake solids of a content of 3-35%total dry solids.

In some embodiments of the present disclosure, a minimum temperature of75 degrees Celsius for 20-40 minutes is required to preventresuscitation and regrowth of indicator and pathogens.

In some embodiments of the present disclosure, the microbial hydrolysisrates are improved by decreasing microbe to substrate proximity,microbe-microbe proximity, or increasing diffusivity through decreasedviscosity.

In another embodiment of the invention, the thermal hydrolyses time orpasteurization temperature is controlled directly or indirectly based onviscosity characteristics of the solids. The indirect control is basedon head loss in pumps, torque in a mixer, and direct control is based onan in-line or off-line or lab measured viscosity.

In another embodiment of the invention, solid dilution or thickening isused to control viscosity of solids.

The pasteurization process can use heat recovered from the ThermalHydrolysis (or Thermal Carbonization) process by either mixing thesolids streams or by using heat exchangers.

In some embodiments of the present disclosure, sterilized solids arebioaugmented with specialized micro-organisms to promote anaerobicdigestion, dewatering and agricultural use of solids. The specializedmicro-organisms may be used to consume hydrogen, to increase Firmicutesover Bacteroidetes ratio, or increase anaerobic nitrogen fixation.

It is understood that the various disclosed embodiments are shown anddescribed above to illustrate different possible features of thedisclosure and the varying ways in which these features may be combined.Apart from combining the features of the above embodiments in varyingways, other modifications are also considered to be within the scope ofthe disclosure. The disclosure is not intended to be limited to thepreferred embodiments described above, but rather is intended to belimited only by the claims set out below. Thus, the disclosureencompasses all alternate embodiments that fall literally orequivalently within the scope of these claims.

The invention is not limited to the structures, methods andinstrumentalities described above and shown in the drawings. The claimsproposed are examples and additional claims or modifications of theseclaims are likely. The invention is defined by the claims set forthbelow. What is claimed and desired to be protected by Letters Patent ofthe United States is:

1. An apparatus for Hydrolysis (or Thermal Carbonization) treatment wherein temperature of wastewater solids is increased between 60 and 220 degrees Celsius to decrease digester volume requirements, increase throughput rates of anaerobic treatment, increase cake solids, improve microbial hydrolysis rates, inactivate pathogens or indicators, or decrease head loss, mixing or pumping energy, and that reduces viscosity of the solids; a. wherein the mostly waste activated sludge, cellulosic waste, slowly digestible organic waste is hydrolyzed (using thermal, thermophilic aerobic, chemical, enzyme, or electron beam) at temperatures between 60 and 180 degrees Celsius (or up to 220 degrees Celsius for thermal carbonization) and; b. wherein the mostly primary solids, food waste or any other organic waste or products is pasteurized at temperatures between 60 and 100 degrees Celsius, or
 2. The apparatus as described in claim 1 further comprising a dewatering mechanism capable of dewatering the solids produced after treatment to increase cake solids of a content of 7-55% total dry solids prior to anaerobic digestion or composting of these solids.
 3. The apparatus described in claim 1 further comprising piping connecting the removed liquid of the dewatering process to the biological nutrient removal, anaerobic digestion, capable of using it as a carbon source.
 4. The apparatus described in claim 3 further comprising a mechanism for harvesting as a sterilized product for agriculture, fermentation feed stock, antimicrobial blends, or chelation the removed liquid of the dewatering process.
 5. The apparatus as described in claim 3 wherein the dewatering mechanism is capable of retaining in the removed liquid of the dewatering process any humic and fulvic substances.
 6. The apparatus as described in claim 1 further comprising a device to dewater the solids produced after additional anaerobic digestion enough to increase cake solids to a content of 7-55% total dry solids.
 7. The apparatus as described in claim 1 further comprising a device to dewater the solids produced before treatment to increased cake solids of a content of 3-35% total dry solids.
 8. The apparatus as described in claim 1 further comprising any number of components to regulate a minimum temperature of 75 degree Celsius for 20-40 minutes as required to address resuscitation and regrowth of indicator and pathogens.
 9. The apparatus as described in claim 1 further comprising devices for decreasing the microbe to substrate proximity, microbe-microbe proximity, or increasing diffusivity through decreased viscosity such that the microbial hydrolysis rates are improved.
 10. The apparatus as described in claim 1 further comprising components in pasteurization to regulate temperature directly or indirectly based on viscosity characteristics of the solids.
 11. The apparatus as described in claim 7 further comprising system of devices calculates head loss in pumps, torque in a mixer to regulate indirect control and in-line or off-line or lab measured viscosity may be used to regulate direct control.
 12. The apparatus as described in claim 1 further comprising solid dilution or thickening devices to control viscosity of solids.
 13. The apparatus as described in claim 1 further comprising mixers in the solid streams or heat exchangers for recovering heat from the Thermal Hydrolysis (or Thermal Carbonization) process.
 14. The apparatus as described in claim 1 further comprising a reactor for retaining sterilized solids are bioaugmented with specialized micro-organism to promote anaerobic digestion, dewatering and agricultural use of solids.
 15. The apparatus as described in claim 13 further comprising any number of devices for retaining the sterilized solids long enough for the specialized micro-organisms are used to consume hydrogen, to increase Firmicutes over Bacteroidetes ratio or increase anaerobic nitrogen fixation.
 16. The apparatus of claim 1 wherein the production of refractory substances during the thermal hydrolysis or carbonization processes are managed or controlled using a sensor that controls a pump, valve or other devices.
 17. The apparatus of claim 1 wherein the production of refractory substances during thermal hydrolysis or carbonization is minimized through more rapid heat dissipation using better mixing, heat transfer or heat management approaches.
 18. The apparatus of claim 1, wherein the temperature can be increases using solar energy or solar cells that directly or indirectly heat sludge.
 19. An apparatus for Hydrolysis (or Thermal Carbonization) treatment comprising: a reactor, wherein temperature of wastewater solids is increased between 60 and 220 degrees Celsius to decrease digester volume requirements, increase throughput rates of anaerobic treatment, increase cake solids, improve microbial hydrolysis rates, inactivate pathogens or indicators, or decrease head loss, mixing or pumping energy, and that reduces viscosity of the solids, wherein more viscous waste streams are hydrolyzed (using thermal, thermophilic aerobic, chemical, enzyme, or electron beam) at temperatures between 60 and 180 degrees Celsius (or up to 220 degrees Celsius for thermal carbonization), wherein the less viscous waste stream is hydrolyzed and/or pasteurized between 60 and 100 degrees Celsius, and wherein the heat generator can regulate higher temperatures of 135 to 180 degrees Celsius as reserved for the higher viscosity solids or less digestible solids; and a dewatering mechanism, wherein the stream for the high-temperature hydrolyses (or carbonization) process is dewatered to a solids concentration of approximately >8, while the stream for the pasteurization or low temperature hydrolysis process is thickened to a solids concentration of approximately <8% in order to manage the relative viscosities and the heat balances of the two streams. 